diff --git a/src/main/java/com/ivory/ivory/domain/Apply.java b/src/main/java/com/ivory/ivory/domain/Apply.java
index 8c5220f..bbf358f 100644
--- a/src/main/java/com/ivory/ivory/domain/Apply.java
+++ b/src/main/java/com/ivory/ivory/domain/Apply.java
@@ -47,11 +47,11 @@ public class Apply extends BaseEntity {
     @JoinColumn(name="child_id")
     private Child child;
 
-    @OneToOne
+    @ManyToOne
     @JoinColumn(name="medical_certificate_id")
     private MedicalCertificate medicalCertificate;
 
-    @OneToOne
+    @ManyToOne
     @JoinColumn(name="absence_certificate_id")
     private AbsenceCertificate absenceCertificate;
 
diff --git a/src/main/java/com/ivory/ivory/service/KakaoPayService.java b/src/main/java/com/ivory/ivory/service/KakaoPayService.java
index d009dfd..5048f48 100644
--- a/src/main/java/com/ivory/ivory/service/KakaoPayService.java
+++ b/src/main/java/com/ivory/ivory/service/KakaoPayService.java
@@ -60,7 +60,7 @@ public KakaoPayReadyDto kakaoPayReady(Long applyId) {
         parameters.put("total_amount",copay);
         parameters.put("vat_amount","200");
         parameters.put("tax_free_amount","0");
-        parameters.put("approval_url","http://localhost:3000/apply/payments/success"); //TODO: 추후 배포된 도메인으로 수정해야함
+        parameters.put("approval_url","https://danpoong-ivory.vercel.app/apply/payments/success"); // 도메인
         parameters.put("fail_url","http://localhost:3000/apply/payments/fail");
         parameters.put("cancel_url","http://localhost:3000/apply/payments/cancel");